Ruler



UNITED STATES PATENT OFFICE.

JOHN E. MANN, OF CLEVELAND, OHIO.

RULER.

SPECIFICATION forming part of Letters Patent No. 299,993, dated June 10, 1884-.

Application filed April 28, 1884. (No model.)

To 0046 whom it may concern:

Be it known that I, JOHN E. MANN, of Cleveland, in the county of Guyahoga and State of Ohio, have invented certain new and useful Improvements in Rulers, of which the following is a specification.

This invention relates to rulers; and it consists in the peculiar manner of attaching the ebony or other suitable wood.

B is a metal blade having a measuring-scale marked off on one side, and is secured to the rule A in a peculiar manner. If the rule be tubular, a core, 0, is secured in the bore at suitable distances from each end, to form a solid portion. In one side of this rule is cut a slot, 0, nearly the full length, leaving a short portion of the rule uncut at the ends, said slot extending about one-third depth into the solid part or core 0. ,The blade B has its inner edge out to fit into the said slot, the ends having notches b b, to fit over the outside of the uncut portion of the rule. The not-ch b has a beveled shoulder to fit into and catch out the beveled edge a at the end of slot 0.

D is an extension of the blade B, and is provided with spurs d d, which, when forced into the core or solid portion of the rule, secures the blade firmly in place. The manner of placing the blade in the rule is to first insert the beveled shoulder 12 in the slot against the beveled edge a, and then force down the extension D, and driving the spurs (Z d into the solid core.

Having described my invention, I claimlhe combination, with the ruler A, having the slot 0, with beveled edge a, of the blade B, having notches b b, and the extension D, provided with spurs d d, substantially as described.

JOHN E. MANN.

WVitnesses:

G110. W. TIBBITTS, M. G. NORTON. 

